The use of light emitting diodes (LED) as part of lighting devices, such as lamps, torches, signalling elements, etc., is known. In many of these applications, LEDs have taken over from other lighting alternatives, due, among others, to great reliability, lighting efficiency, and ease of integration due to size and efficiency.
In these lighting devices with LEDs, there is often a structure in which one or more LEDs are connected or integrated to a support, for example a printed circuit board (PCB), on which there are included one or more optical elements acting on the light emitted by the LEDs (for example, combining it with the light of other LEDs by means of lenses) or serving as protection (for example, layers of plastic materials).
For example, ES 1 066 568 U presents an optical light emitting system based on LEDs suitable for beacons of navigation aid systems, with a large requirement for energy efficiency. To adapt to this requirement, the system includes a Fresnel lens cylindrically symmetrical with respect to the focal axis of the lens, in addition to other geometric characteristics detailed in the specification. This lens collects the light emitted by the LEDs and forms a narrow beam of light vertically (between 3° and)8°, while covering 120° horizontally.
Another application is presented in ES 2 197 498 T3, in this case for luminous signalling in the railway environment. In addition to combining a high number of diodes to achieve the necessary luminous intensity, the device specifically has a side lens which allows checking its correct operation.
However, there is still the need for lighting devices based on LEDs optimising the lighting efficiency thereof both in terms of light transmission within the device itself and in terms of adaptation of the light emitted to the specific scenario in which the device is located, such as for example, in long and narrow areas such as corridors or square areas.